I'm guessing everyone wants to have that gauntlet Warren Stone got at the end of "Stuck Together". We know in that episode that the Foot Luntenant and Foot Brute were after it, likely because it is associated with the Shredder. However, they were thwarted. Then Warren Stone saw it, said "That looks useful" and took it for himself. Stone is largely a villain who is just there as a joke, so naturally, other villains such as Hypnopotamus are going to want to have it for themselves before it falls back into the hands of the Foot Clan.

Personal opinion of 'Rise' aside... the only comfort in the Turtles (at least in the modern incarnations) in general never winning after multiple times nominated is that we seem to be far from the only fandom that's tired of the same outcome time after time.

Edit: Although come to think of it.... if this was legitimately based on real votes, would the outcome necessarily be the same if Spongebob was judged ONLY on newer episodes that premiered each year? (Because lets face it, the quality has dropped in the last few years.) Rather than keep being judged on a majority of episodes that are a lot older than the kids voting for them. After all, the earliest eps will be turning 20 this year. What other property gets to win over and over based on something it came out with 20 years ago...